CORNWALL’S Suez-run waste incinerator at St Dennis, known as the Cornwall Energy Recovery Centre, is failing the people it was built to serve, writes CASA (Climate Action St Austell).

In 2024, it burned 231,633 tonnes of household waste, generating tens of thousands of tonnes of ash. Most worrying of all, 8,187 tonnes of toxic fly ash were loaded into tankers and hauled on punishing 700-mile round trips to Northamptonshire every single week. Every journey poured more carbon into the atmosphere at a time when Cornwall has declared a climate emergency.

The problems do not end there. This summer, boiler damage forced one of the incinerator’s lines out of action. With the second line taken down for scheduled maintenance in September, Cornwall was temporarily left without a functioning incinerator. When this happened, every tonne of household waste was being driven out of the county, some of it to landfill, at enormous environmental and financial cost.

Instead of providing a modern, safe solution to Cornwall’s waste, the facility has become a liability – generating more emissions, more transport miles and more carbon than promised, while draining taxpayer money.

We must demand answers. Why, in the middle of a climate emergency, is a facility sold as “energy recovery” fuelling the crisis it was supposed to help solve?

The people of Cornwall deserve better than toxic ash – which Suez calls air pollution control residue (APCR) – and rising carbon.

The Voice gave Suez the opportunity to respond to the CASA criticisms. Below are some of the points Suez has responded with.

Cornwall Energy Recovery Centre accepts up to 240,000 tonnes of non-recyclable household waste each year across two processing lines. There are three main by-products: bottom ash which is processed at an onsite facility to produce secondary aggregate; electricity for the local distribution network; and air pollution control residue (APCR).

The APCR has a high alkaline content so has to be sent to an appropriately licensed facility. There are a limited number of these across the country and currently this is transported to the nearest facility.

One of the two processing lines at the centre will undergo extended repairs after its boiler experienced a fault. The programme of repairs will take around six months to complete. Whilst repairs are made, it may also be necessary to divert some waste during seasonal peaks in waste production, such as Christmas. If we cannot find capacity at other energy recovery facilities, some waste will be sent to landfill during this period. However, this would be as a last resort.

The other line is due now to be back up and running following yearly planned maintenance which means that the majority of the waste will continue to be processed as normal. When both lines were down, we diverted waste, making every effort to secure capacity at other energy recovery facilities in the region to minimise waste sent to landfill.

Over the past five years, the facility has had a strong operational track record, it has achieved 91 per cent availability – this is best practice.